Contaminación bacteriana de Productos Cárnicos Ovinos Comercializados en la Meseta Central de México

El estudio se realizó para evaluar la contaminación microbiológica de las canales de ovino comercializadas en el Altiplano Central Mexicano, durante el período Primavera - Verano 2012. Se recolectaron muestras en tres expendios mayoristas de las canales de ovino antes de la refrigeración, las manos de los trabajadores, y los cuchillos, utilizando la técnica de hisopo húmedo. Las muestras se analizaron para Cuenta Total de Aerobios Viables (TAVC), Cuenta Coliformes Totales (CCT) y Cuenta Coliformes Fecales (FCC), los conteos se determinaron por el método de recuento estándar en placa. Las medias de TAVC de las canales de ovino, las manos del personal, y los cuchillos fueron de 0,99 ± 0,81, 0,78 ± 0,53y 1,84 ± 0,28 log10UFC / mL, respectivamente; no se encontraron diferencias estadísticamente significativas (P <0,05). La media de TCC para las canales fue de 0,74 ± 0,56 log10 UFC / mL y 0,36 ± 0,48 log10UFC/mL para cuchillos, no se encontraron diferencias estadísticamente significativas (P <0,05). No se detectaron FCC en las canales de ovino, el personal y los cuchillos. Los resultados indicaron buenas condiciones higiénicas y de manipulación durante los canales de comercialización

Effects of cellulase and xylanase enzymes mixed with increasing doses of Salix babylonica extract on in vitro rumen gas production kinetics of a mixture of corn silage with concentrate

Therefore, the objective of this study was to assess the effects of different doses of plant extracts when combined with exogenous fibrolytic enzymes on in vitro ruminal fermentation of a mixture of corn silage with concentrate.An in vitro gas production (GP) technique was used to investigate the effects of combining different doses of Salix babylonica extract (SB) with exogenous fibrolytic enzymes (EZ) based on xylanase (X) and cellulase (C), or their mixture (XC; 1:1 v/v) on in vitro fermentation characteristics of a total mixed ration of corn silage and concentrate mixture (50:50, w/w) as substrate. Four levels of SB (0, 0.6, 1.2 and 1.8 mL g–1 dry matter (DM)) and four supplemental styles of EZ (1 μL g–1 DM; control (no enzymes), X, C and XC (1:1, v/v) were used in a 4×4 factorial arrangement. In vitro GP (mL g–1 DM) were recorded at 2, 4, 6, 8, 10, 12, 24, 36, 48 and 72 h of incubation. After 72 h, the incubation process was stopped and supernatant pH was determined, and then filtered to determine dry matter degradability (DMD). Fermentation parameters, such as the 24 h gas yield (GY24), in vitro organic matter digestibility (OMD), metabolizable energy (ME), short chain fatty acid concentrations (SCFA), and microbial crude protein production (MCP) were also estimated. Results indicated that there was a SB´EZ interaction (P<0.0001) for the asymptotic gas production (b), the rate of gas production (c), GP from 6 to 72 h, GP2 (P=0.0095), and GP4 (P=0.02). The SB and different combination of enzymes supplementation influenced (P<0.001) in vitro GP parameters after 12 h of incubation; the highest doses of SB (i.e., 1.8 mL g–1 DM), in the absence of any EZ, quadratically increased (P<0.05) the initial delay before GP begins (L) and GP at different incubation times, with lowering b (quadratic effect, P<0.0001) and c (quadratic effect, P<0.0001; linear effect, P=0.0018). The GP was the lowest (P<0.05) when the highest SB level was combined with cellulose. There were SB´EZ interactions (P<0.001) for OMD, ME, the partitioning factor at 72 h of incubation (PF72), GY24, SCFA, MCP (P=0.0143), and pH (P=0.0008). The OMD, ME, GY24 and SCFA with supplementation of SB extract at 1.8 mL g–1 DM were higher (P<0.001) than the other treatments, however

Antimicrobial resistance of three common molecularly identified pathogenic bacteria to Allium aqueous extracts

The aim of this work was to evaluate the in vitro bacterial inhibition of different types of garlic on Escherichia coli ATCC 25922, Listeria monocytogenes and Staphylococcus aureus. The bacterial strains were molecularly identified using gen 16S rDNA molecular identification. Four different types of garlics were used: 1) white, 2) Japanese, 3) elephant and 3) black, and these were evaluated at two different concentrations (0.25 and 0.125 g/mL) per garlic type. Bioactive compounds present in the garlics were identified using high-performance liquid chromatography coupled to ultraviolet detector (HPLC-UV), and total polyphenols were quantified by the Folin-Ciocalteu technique. The Kirby-Bauber method was used for the bacterial evaluation. Aqueous extract of black garlic had the highest amount of polyphenols 6.26 ± 0.21 mg GAE/mL. The area of inhibition was measured and classified as sensitive, intermediate or resistant. Using the disc diffusion assay, higher concentration (0.25 g/mL) of aqueous extract of white garlic had the highest antibacterial activity area, with 21.46 ± 3.94 mm for L. monocytogenes, 20.61 ± 2.47 mm for S. aureus and 17.83 ± 2.21 mm for E. coli. White garlic had comparable antimicrobial activity as the control (tetracycline at 30 μg) as indicated by the size of the inhibition halos. Based on your results, white garlic can be used as an alternative to synthetic antimicrobials. 1. Introduction Previously, natural products were used to combat diseases, however, with the discovery of synthetic antibiotics, they were gradually replaced [1,52,53]. Natural products used to be the major ingredient of many drugs but pharmaceutical companies have decreased or even eliminated research on natural products [2,42–46,52]. The focus has been on synthetic antibiotics and their indiscriminate use have reduced their effectiveness against infectious diseases in addition to incidences of antibiotics resistance [3,47–50]. Foodborne diseases are still a public health problem worldwide and the causal agents are mainly Escherichia coli O157: H7, Salmonella spp., Listeria monocytogenes, and Clostridium botulinum [4,5]. Bacteria have the ability to adapt to an environment and develop resistance mechanisms, which can be of natural or acquired origin [6,7,51]. Due to the current problems of antibiotics resistance facing the livestock industry, natural products can be viable and economical al ternatives [55,63]. One of such natural